Asymmetric blade locking apparatus

The work leading to this invention has received funding from the European Union (EU) Open Fan for Environmental Low Impact of Aviation (OFELIA) project. In particular, this invention was made with government support under OFELIA Grant agreement ID: 101102011 funded by the EU.

This disclosure relates generally to aircraft engines and, more particularly, to asymmetric blade locking apparatus.

Many gas turbine engines include a rotor assembly that includes a rotor disk and an array of rotor blades that extend radially outward from a perimeter of the rotor disk. The rotor blades may be formed separately from the rotor disk and then attached thereto. In particular, in some applications, the rotor blades may be inserted into a rim slot disposed along a circumference of a rotor disk. In many instances, it may be beneficial to retain the array of rotor blades in a fixed circumferential arrangement such that the rotor disk and the array of rotor blades rotate together in the fixed arrangement.

In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. The figures are not necessarily to scale.

As used herein, the terms “dovetail” or “dovetail shape” refer to structures or shapes having a relative wide portion that tapers to a relatively narrow portion in the radial direction.

As used herein, the terms “axial” and “axially” refer to directions and orientations that extend substantially parallel to a centerline of a turbine engine. Moreover, the terms “radial” and “radially” refer to directions and orientations that extend substantially perpendicular to the centerline (e.g., a rotational axis) of the turbine engine. In addition, as used herein, the terms “circumferential” and “circumferentially” refer to directions and orientations that extend arcuately about the centerline of the turbine engine.

The terms “forward” and “aft” refer to relative positions within a turbine engine or vehicle, and refer to the normal operational attitude of the turbine engine or vehicle. For example, with regard to a turbine engine, forward refers to a position closer to an engine inlet and aft refers to a position closer to an engine nozzle or exhaust.

As used herein, a “radius” of a feature of an airfoil refers to a distance from an axial centerline (e.g., an axis of rotation) of an unducted propulsion system to the feature of the airfoil in a direction perpendicular to the axial centerline (i.e., a radial direction).

The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.

“Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc., may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and/or” when used, for example, in a form such as A, B, and/or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, or (7) A with B and with C. As used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B.

As used herein, singular references (e.g., “a”, “an”, “first”, “second”, etc.) do not exclude a plurality. The term “a” or “an” object, as used herein, refers to one or more of that object. The terms “a” (or “an”), “one or more”, and “at least one” are used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements, or actions may be implemented by, e.g., the same entity or object. Additionally, although individual features may be included in different examples or claims, these may possibly be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and/or advantageous.

As used herein, unless otherwise stated, the term “above” describes the relationship of two parts relative to Earth. A first part is above a second part, if the second part has at least one part between Earth and the first part. Likewise, as used herein, a first part is “below” a second part when the first part is closer to the Earth than the second part. As noted above, a first part can be above or below a second part with one or more of: other parts therebetween, without other parts therebetween, with the first and second parts touching, or without the first and second parts being in direct contact with one another.

As used in this patent, stating that any part (e.g., a layer, film, area, region, or plate) is in any way on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween.

As used herein, connection references (e.g., attached, coupled, connected, and joined) may include intermediate members between the elements referenced by the connection reference and/or relative movement between those elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and/or in fixed relation to each other. As used herein, stating that any part is in “contact” with another part is defined to mean that there is no intermediate part between the two parts.

Unless specifically stated otherwise, descriptors such as “first,” “second,” “third,” etc., are used herein without imputing or otherwise indicating any meaning of priority, physical order, arrangement in a list, and/or ordering in any way, but are merely used as labels and/or arbitrary names to distinguish elements for ease of understanding the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as “second” or “third.” In such instances, it should be understood that such descriptors are used merely for identifying those elements distinctly within the context of the discussion (e.g., within a claim) in which the elements might, for example, otherwise share a same name.

Examples disclosed herein enable blade platforms to come together (e.g., be in contact) at a circumferential position that unevenly divides a circumferential gap between adjacent dovetails, which extend radially inward from the blade platforms and couple to a rotating disc. In some examples, an asymmetric locking lug is coupled to a set screw that extends from the disc to an orifice between the blade platforms. Specifically, the locking lug can be asymmetric on opposite sides of a hole through which the set screw extends in a circumferential direction defined by an engine including the blade platforms. The asymmetric locking lug contacts the adjacent dovetails to maintain a relative circumferential position of the dovetails. For example, the locking lug can include a longer circumferential side to contact a first dovetail, and a shorter circumferential side to contact a second dovetail. Thus, the locking lug enables the blade platforms to meet at a circumferential location that unevenly splits the circumferential gap between the dovetails.

Further, the asymmetric locking lug is structured to position a center of gravity of the locking lug aligned with a longitudinal axis of the set screw. For example, a longer circumferential side of the asymmetric locking lug can include a recess and/or a shortened axial length relative to a shorter circumferential side of the locking lug positioned on an opposite side of the longitudinal axis in the circumferential direction. As such, the structure of the locking lug prevents the locking lug from encountering a moment at either end of the set screw that would otherwise dislodge the locking lug.

Some examples include a locking lug that is symmetrical on opposite circumferential sides of the longitudinal axis. In such examples, a central axis of the symmetric locking lug (e.g., the longitudinal axis of the set screw coupled to the locking lug) is still aligned with the circumferential position at which the blade platforms come together and unevenly divide the circumferential gap between the adjacent dovetails. In such examples, one of the adjacent dovetails includes a circumferential protrusion to contact a surface of the symmetric locking lug.

Referring now to the drawings,is a schematic cross-sectional view of an example gas turbine enginethat can include example blade locking assemblies in accordance with examples disclosed herein. The example gas turbine enginecan be implemented on an aircraft and therefore referred to as an aircraft engine. In this example, the gas turbine engineis a turbofan-type of engine. However, the principles of the present disclosure are also applicable to other types of engines, such as turboprop engines and engines without a nacelle, such as unducted fan (UDF) engines (sometimes referred to as propfans). Further, the examples disclosed herein can be implemented on other types of gas turbines, such as non-aircraft engines and/or power generators.

As shown in, the gas turbine engineincludes an outer bypass duct(which may also be referred to as a nacelle, fan duct, or outer casing), a core turbine engine, and a fan section. The core turbine engineand the fan sectionare disposed at least partially in the outer bypass duct. The core turbine engineis disposed downstream from the fan sectionand drives the fan sectionto produce forward thrust.

As shown in, the gas turbine enginedefines a longitudinal or axial centerline axisextending therethrough for reference.also includes an annotated directional diagram with reference to an axial direction A, a radial direction R, and a circumferential direction C. In general, as used herein, the axial direction A is a direction that extends generally parallel to the axial centerline axis, the radial direction R is a direction that extends orthogonally outward from or inward toward the axial centerline axis, and the circumferential direction C is a direction that extends concentrically around the axial centerline axis. Further, as used herein, the term “forward” refers to a direction along the centerline axisin the direction of movement of the gas turbine engine, such as to the left in, while the term “rearward” refers to a direction along the centerline axisin the opposite direction, such as to the right in.

The core turbine engineincludes an outer casing(which may also be referred to as a mid-casing), which is substantially tubular and defines an annular inlet. The outer casingof the core turbine enginecan be formed from a single casing or multiple casings. The outer casingencloses, in serial flow relationship, a compressor section having a booster or low pressure compressor(“LP compressor”) and a high pressure compressor(“HP compressor”), a combustor(e.g., a combustion section), a turbine section having a high pressure turbine(“HP turbine”) and a low pressure turbine(“LP turbine”), and an exhaust section.

The core turbine engineincludes a high pressure shaft(“HP shaft”) that drivingly couples the HP turbineand the HP compressor. The core turbine enginealso includes a low pressure shaft(“LP shaft”) that drivingly couples the LP turbineand the LP compressor. The LP shaftalso couples to a fan shaft.

The fan sectionincludes a plurality of fan bladesthat are coupled to and extend radially outward from the fan shaft. In some examples, the LP shaftmay couple directly to the fan shaft(i.e., a direct-drive configuration). In alternative configurations, the LP shaftmay couple to the fan shaftvia a reduction gear(i.e., an indirect-drive or geared-drive configuration). While in this example the core turbine engineincludes two compressors and two turbines, in other examples, the core turbine enginemay only include one compressor and one turbine. Further, in other examples, the core turbine enginecan include more than two compressors and turbines. In such examples, the core turbine enginemay include more than two drive shafts or spools.

As illustrated in, during operation of the gas turbine engine, airenters an inlet portionof the gas turbine engine. The airis accelerated by the fan blades. A first portionof the airflows into a bypass airflow passage, while a second portionof the airflows into the annular inletof the core turbine engine(and, thus, into the LP compressor). Downstream of the annular inlet, one or more sequential stages of LP compressor stator vanesand LP compressor rotor bladescoupled to the LP shaftprogressively compress the second portionof the airflowing through the LP compressoren route to the HP compressor. Next, one or more sequential stages of HP compressor stator vanesand HP compressor rotor bladescoupled to the HP shaftfurther compress the second portionof the airflowing through the HP compressor. This provides compressed airto the combustorwhere it mixes with fuel and burns to provide combustion gases. Fuel is injected into the combustorby one or more nozzles. The gas turbine engineincludes a compressor frameto support a forward portion of the core turbine engine. The LP compressor rotor bladescan be coupled to the LP shaftand/or the HP compressor rotor bladescan be coupled to the HP shaftvia a blade locking assembly, as discussed in further detail in connection with.

The combustion gasesflow through the HP turbinewhere one or more sequential stages of HP turbine stator vanesand HP turbine rotor bladescoupled to the HP shaftextract a first portion of kinetic and/or thermal energy. This energy extraction supports operation of the HP compressor. The combustion gasesthen flow through the LP turbinewhere one or more sequential stages of LP turbine stator vanesand LP turbine rotor bladescoupled to the LP shaftextract a second portion of thermal and/or kinetic energy therefrom. This energy extraction causes the LP shaftto rotate, which supports operation of the LP compressorand/or rotation of the fan shaft. The combustion gasesthen exit the core turbine enginethrough the exhaust sectionthereof. The combustion gasesmix with the first portionof the airfrom the bypass airflow passage. The combined gases exit an exhaust nozzle(e.g., a converging/diverging nozzle) of the bypass airflow passageto produce propulsive thrust. The gas turbine engineincludes a turbine frameto support an aft portion of the core turbine engine. In some examples, the turbine frameis positioned downstream of the LP turbine. The HP turbine rotor bladescan be coupled to the HP shaftand/or the LP turbine rotor bladescan be coupled to the LP shaftvia a blade locking assembly, as discussed in further detail in connection with.

It should be appreciated that the example gas turbine enginedepicted inis by way of example only, and that in other examples, the gas turbine enginemay have any other suitable configuration. Accordingly, it will be appreciated that in other examples, the gas turbine engine, which is configured as a turbofan engine in, may instead be configured as, e.g., a turbojet engine, a turboshaft engine, a turboprop engine, etc.

illustrate a portion of an example blade locking assembly(e.g., an asymmetric blade locking apparatus) that can be implemented in the engineofin accordance with the teachings disclosed herein.shows an aft-looking-forward view of the blade locking assembly;shows a forward-looking-aft view of the blade locking assembly;shows a radially inward view of the blade locking assembly; andshows a radially outward view of the blade locking assembly.

In the illustrated example of, the blade locking assemblyincludes a plurality of platforms(e.g., a circumferential row of platforms). As shown in, the blade locking assemblyincludes bladesextending from an outer radial surfaceof the platforms. As shown in, the blade locking assemblyincludes dovetailsextending from an inner radial surfaceof the platforms. The bladescan correspond to the LP compressor rotor blades, the HP compressor rotor blades, the HP turbine rotor blades, and/or the LP turbine rotor bladesof. Accordingly, the bladesdepicted form a portion of a row of annular rotor blades extending from consecutive platforms(e.g., adjacent platforms in the circumferential direction C) in the engineof.

In this example, as shown in, the bladesinclude a main bladeand a splitter bladeextending from each of the platforms. In this example, the bladesare staggered for clockwise rotation (e.g., in the aft-looking-forward perspective of). Alternatively, the bladescan be configured for counterclockwise rotation (e.g., in the aft-looking-forward perspective of). Additionally, the blade locking assemblycan alternatively include a different number of the bladesextending from each of the platforms. For example, the blade locking assemblycan include only the main bladeextending from the platformor only the splitter blade. Alternatively, the blade locking assemblycan include more than two of the bladesextending from each of the platforms.

To couple the platformsand, in turn, the bladesto the HP shaftand/or the LP shaftof, the dovetailsare positioned within a rim slot along a circumference of a rotor disk associated with the HP shaftand/or the LP shaft. To inhibit relative movement between the dovetails, and, in turn, the platformsand the blades, the blade locking assemblyincludes locking lugs() in contact with the dovetails. Specifically, the locking lugsare positioned in alternating gaps(e.g., every other of the gapsin the circumferential direction C) between adjacent dovetails. As shown in, the locking lugscontact circumferential surfacesA,B (e.g., surfaces that face the circumferential direction C, circumferentially facing surfaces) of adjacent dovetailsA,B. The circumferential surfacesA,B face opposite directions along the circumferential direction C (e.g., clockwise and counterclockwise) and, thus, face each other.

Additionally, as shown in, the blade locking assemblyincludes radial set screws.illustrate isolated perspective views of one of the locking lugofand the radial set screws. The locking lugsinclude a tower(e.g., a radially outward projection) extending radially outward from a first portion(e.g., a mid-portion) of the locking lug. The towerand the first portionof the locking lugdefine a radial hole(e.g., a radial orifice) to receive the radial set screw. Specifically, a first end(e.g., a radially inward end) of the radial set screwcontacts the disc associated with the HP shaftor the LP shaftthat couples to the dovetails. As the radial set screwrotates, the locking lugmoves radially outward to cause corners of the locking lugto contact pressure faces of the disc. The contact between the corners of the locking lugand the pressure faces of the disc form a primary locking mechanism to position the locking lugon the disc. Additionally, the towerof the locking lugdefines a forward-aft extruded region(e.g., positioned forward and aft of the radial set screwand aligned with the radial set screw in the circumferential direction C). The forward-aft extruded regionis positioned in a recess of the disc associated with the HP shaftor the LP shaftto inhibit circumferential movement of the locking lugand form a secondary locking mechanism.

Further, a second endof the radial set screwextends to an openingdefined between circumferential edgesA,B of adjacent platformsA,B, as shown in. Specifically, the circumferential edgesA,B include cut-outsA,B to provide clearance for the second endof the radial set screw. Accordingly, the second endof the radial set screwcan define a portion of a boundary of the flow path of the airin the core turbine engineof, with the outer radial surfacesof the platforms. Thus, the second endof the radial set screwcan be flush with the outer radial surfaces. In some examples, the towerextends to the openingand is flush with the outer radial surfacesof the platforms, similar to the radial set screw. In this example, the locking lugs, advantageously, enable the circumferential edgesA,B of the adjacent platformsA,B to unevenly divide the gapbetween the adjacent dovetailsA,B in the circumferential direction C.

is a schematic illustration of the gapbetween the adjacent dovetailsA,B. In, the circumferential surfaceA of the first dovetailA defines a first geometric plane, and the circumferential surfaceB of the second dovetailB defines a second geometric plane. In, a centerlineevenly divides an arcbetween the geometric planes,(e.g., extending from the first geometric planeto the second geometric plane). A platform opening geometric planespans in the radial direction R and the axial direction A and is aligned with the opening() defined between the circumferential edgesA,B of adjacent platformsA,B.

As shown in, the platform opening geometric planedoes not align with the centerlineof the gapin the circumferential direction C. For example, circumferential clocking of the bladesto balance stresses encountered at the dovetailcan result in the platform opening geometric planeoccupying a different circumferential position than the centerline. In some examples, such circumferential clocking is beneficial when two or more of the blades(e.g., the main bladeand the splitter blade) extend from the same platform. In some examples, such circumferential clocking is beneficial when one of the blades(e.g., only the main blade) extends from the platform.

Advantageously, the locking lugsenable the platform opening geometric planeto be positioned at different locations along the arcwithin 40% of a span of the arcfrom the centerlinein either direction (e.g., clockwise and counterclockwise). Specifically, the platform opening geometric planecan be aligned with or positioned between a 10% radial geometric plane(e.g., at 10% of the span of the arcfrom the second circumferential surfaceB towards the first circumferential surfaceA) and a 90% geometric plane(e.g., at 90% of the span of the arcfrom the second circumferential surfaceB towards the first circumferential surfaceA) while still enabling preferred circumferential clocking of the blades(e.g., for stress balance and frequency tuning).

Returning to the illustrated examples of, the locking lugand the radial set screwdefine a set screw axis, which also corresponds to a central axis of the radial hole. Accordingly, the set screw axisspans in the radial direction R (). As the radial set screwextends to the opening() between the platformsA,B, the set screw axisaligns with the platform opening geometric plane() in the circumferential direction C (). Thus, the set screw axisis offset from the centerlinein the circumferential direction C, similar to the platform opening geometric plane. In some examples, space is maintained between the towerand the circumferential surfacesA,B in the circumferential direction C during operation. Accordingly, the toweris separated from the first circumferential surfaceA and the second circumferential surfaceB by different distances in the circumferential direction C (e.g., at a radius of the tower).

To enable the circumferential edgesA,B of the adjacent platformsA,B to unevenly split the gapbetween the dovetailsA,B in the circumferential direction C, the locking lugsinclude a second portion(e.g., a shorter circumferential portion) and a third portion(e.g., a longer circumferential portion) that extend different distances from the first portion(e.g., in the circumferential direction C). Specifically, the second portionof the locking lugsincludes a first circumferential surface(e.g., a first circumferential end of the locking lugs), and the third portionof the locking lugsincludes a second circumferential surface(e.g., a second circumferential end of the locking lugs). The first circumferential surfaceis in contact with the first dovetailA (), and the second circumferential surfaceis in contact with the second dovetailB. The first circumferential surfaceis positioned closer than the second circumferential surfaceto the radial hole(e.g., the set screw axis) in the circumferential direction C to enable the circumferential surfaces,to extend to and contact the circumferential surfacesA,B of the dovetailsA,B.

To prevent the locking lugfrom dislodging when centripetal forces are encountered as the bladesrotate during engine operations, the locking lugis configured to position a center of gravity() of the locking lugin a same location in the circumferential direction C as the set screw axis. Accordingly, the center of gravityof the locking lugis offset from the centerlinebetween the dovetailsA,B. As such, the locking lugdoes not encounter a moment about the first endor the second endof the locking lugthat would otherwise dislodge the locking lugand enable relative movement between the dovetailsA,B when the bladesrotate.

To configure the center of gravityto align with the set screw axis, the third portionof the locking lugis at least partially hollow to reduce a mass per unit of distance spanned in the circumferential direction C of the third portion. That is, the second portionof the locking lugis heavier than the third portionper unit of circumferential span. Specifically, in the illustrated example of, the third portionof the locking lugsincludes a recess(e.g., a notch, an indent, a depression, etc.) in a radially outward facing surfaceof the third portion. In this example, at least a portion of the recessaligns with the radial holein the axial direction A. Conversely, the second portionof the locking lugis full (e.g., does not include a recess) between an outer radial surface() and an inner radial surface() of the second portion.

Additionally, in the illustrated example of, the third portionof the locking lugincludes an axially shortened sectionthat has a reduced span in the axial direction A relative to the first portionand/or the second portionto reduce the mass per unit of distance spanned in the circumferential direction C (e.g., mass per circumferential span) of the third portion. That is, the first portionand the second portionat least partially span a greater distance than the third portionin the axial direction A. In some examples, the reduced mass per circumferential span of the third portionis configured in a different manner. For example, the third portioncan have a radially inward facing surface () of the third portion. Accordingly, the locking lugis asymmetric on opposite circumferential sides of the set screw axis(e.g., on opposite sides of a geometric plane that includes the set screw axisand spans in the axial direction A) to configure the center of gravityof the locking lugto align with the set screw axiswhile enabling the second portionand the third portionto span different distances in the circumferential direction C. As such, an engagement between the locking lugand the first dovetailA and the second dovetailB is asymmetric relative to the set screw axisand/or the centerlinebetween the dovetailsA,B. The locking lugcan be symmetric on opposite axial sides of the set screw axis(e.g., on opposite sides of a geometric plane that includes the set screw axisand spans in the circumferential direction C) to position the center of gravityat a midpoint of the first portionin the axial direction A. The symmetry on the opposite axial sides of the set screw axisprevents the locking lug from encountering a moment that would otherwise act against the first endand/or the second endin the axial direction A.

is a forward-looking-aft view of a portion of another example blade locking assemblythat can be implemented in the engineof. The blade locking assemblyincludes the plurality of platformsand the bladesextending from the outer radial surfacesof the platforms. Further, blade locking assemblyincludes first dovetailsA and second dovetailsB extending from the inner radial surfacesof the platformsand locking lugsin contact with the dovetailsA,B.

In the illustrated example of, the locking lugsinclude the set screw axis, which is aligned with the platform opening geometric plane() and offset from the centerline(). In this example, the locking lugsare symmetric on opposite sides of the set screw axisin the circumferential direction C. The dovetailsA,B include circumferential surfacesA,B face opposite directions along the circumferential direction C (e.g., clockwise and counterclockwise) and, thus, face each other. In this example, to enable the platform opening geometric planeand the set screw axisto be offset from the centerline, the first dovetailA includes a circumferential projection(e.g., a protrusion) in the circumferential surfaceA. The circumferential projectionis positioned at a same radial distance (e.g., a same distance from the axial centerline axis) as the locking lugand contacts a first circumferential surfaceof the locking lug. The circumferential surfaceB of the second dovetailB contacts a second circumferential surfaceof the locking lug. As a result, an engagement between the locking lugand the first dovetailA and the second dovetailB is asymmetric relative to the set screw axisand/or the centerlinebetween the dovetailsA,B. Further, with the locking lugbeing symmetric on opposite sides of the set screw axisin the circumferential direction C, the locking lugis evenly loaded on opposite sides of the set screw axissuch that the locking lugdoes not shift during operation.

In some examples, to inhibit a center of gravity of the dovetailA from encountering a force imbalance that would dislodge the dovetailA when rotating, the circumferential projectionis mirrored on an opposite circumferential surfaceC of the dovetailA. In some examples, to balance the center of gravity of the dovetailA, a recess is defined in the circumferential surfaceA. In some examples, to balance the center of gravity of the dovetailA, a portion of the circumferential surfaceA outside of the circumferential projectionhas a reduced extension into the gap(e.g., an increased separation from the centerline()) relative to the circumferential surfaceB () that the third portionof the locking lugcontacts in.

In some examples, a turbine engine in accordance with teachings disclosed herein includes means for producing aerodynamic forces. For example, the means for producing aerodynamic forces can be implemented by the bladesof.

In some examples, the turbine engine in accordance with teachings disclosed herein includes means for defining an inner radial surface of a flow path. For example, the means for defining the inner radial surface can be implemented by the platformsof.

In some examples, the turbine engine in accordance with teachings disclosed herein includes means for rotating the means for defining and the means for producing. For example, the means for rotating can be implemented by the HP shaftand/or the LP shaftof.

In some examples, the turbine engine in accordance with teachings disclosed herein includes means for coupling the means for producing and the means for defining to the means for rotating. For example, the means for coupling can be implemented by the dovetails,A,B ofand/or the dovetailsA,B of.

In some examples, the turbine engine in accordance with teachings disclosed herein includes means for asymmetrically splitting a circumferential space between the means for coupling. For example, the means for asymmetrically splitting may be implemented by the locking lugsofand/or the circumferential projectionof.

From the foregoing, it will be appreciated that example systems, apparatus, articles of manufacture, and methods have been disclosed that enable circumferential edges of adjacent blade platforms to meet at a circumferential position that unevenly divides a circumferential gap between dovetails extending radially inward from the blade platforms. As such, examples disclosed herein provide flexibility in circumferential clocking of a blade(s) extending from the platform. Further, examples disclosed herein avoid modifications to rotor discs, to which the dovetails couple, to enable desired clocking to be obtained.